Creating a 4x5-->3x4 reducing back

[Jeremy]

I'm really enjoying the 3.25x4.25 film size (the film dimensions are great!), but I really felt limited tonight when I went out to do some shooting where some more movements would have really helped.

Can anyone give suggestions on how to make a 3x4 back for a 4x5 camera? I was thinking I could get a piece of 1/4" plywood (or other such material) sized the same as the rotating camera back of the 4x5. Then I could just unscrew the 3x4 back from my Crown Graphic (I think this is possible as I just see 4 screws holding it on, but there could also be some glue) and screw it centered onto the plywood with the appropriate hole cut in the middle. Any problems forseen?

Also, if anyone has a 3x4 graphic with a good grafloc back for parts let me know so that I don't have to butcher the crown and I can have a back-up camera, but if I can't find one then I would rather have the field camera....

[Nick Zentena]

Why? 3x4 film isn't cheaper then 4x5. Just shoot 4x5 and crop later.

No. Okay. Which 4x5 camera is this for? I made a new back for my Ansco 5x7 by just cutting some hardboard to the right size. Cut the opening. I then took the hardware and mounted it on the hardboard. Done. You need to make sure the film plane doesn't move. Take depth measurements off the ground glass. You'll want to make sure it's perfectly square. But nothing really complicated.

[Jeremy]

Why? 3x4 film isn't cheaper then 4x5. Just shoot 4x5 and crop later.

Other than the fact that I have 900 sheets of 3x4 in the freezer, 3x4 film is also $10 cheaper/50 sheets than 4x5 film in what I shoot (Efke 100).

The camera is a Shen Hao 4x5.

I am not sure I follow, why do I need to take depth measurements off of the ground glass? If I just screw the 3x4 grafloc back onto the hardwood the ground glass and film plane won't change in relation to each other. Or do you mean to make sure that whatever I get to screw the 3x4 back onto is completely flat and does not introduce a slant into the film plane?

[Nick Zentena]

Just to make sure you haven't moved the film plane some how. If the inside of the ground glass measures the right distance then it should be fine.

[Oren Grad]

I am not sure I follow, why do I need to take depth measurements off of the ground glass? If I just screw the 3x4 grafloc back onto the hardwood the ground glass and film plane won't change in relation to each other.

Jeremy -

You are correct. If you use the back assembly from the 3.25x4.25 Crown intact, then the ground glass to film plane register is preserved and you don't need to worry about it.

And yes, you can just unscrew the back from a 3.25x4.25 Graphic - I did it once to satisfy myself that a project like yours would be possible, though in the end I didn't go through with it.

Good luck...

[Greg Davis]

I made 4x5 and a 2x3 reducing backs for my Kodak Master 8x10 by using the backs from Crown Graphics. I bought the hobby plywood available at craft stores for the job. Get a thickness that is just too thin and buy two pieces of it. Look at which way the warping curves and glue them together to cancel out the bend. I put an extra piece of plywood between this part and the camera back so I can get my fingers under the film holder to pull it out. And don't forget the light trap on the camera side of the whole thing.

-Greg

[Troy Ammons]

I would look on Ebay for a 3x4 crown. They are not that popular, and the prices I have seen are fairly low, especially without a lens.

[Jeremy]

I've been looking on eBay for one, but the cheapest I have found with a graflok back so far has been $150.

[Oren Grad]

Why does it need to have a Graflok back? You don't need one to use 3.25x4.25 sheet film in holders - the plain spring-back will do fine.

[Jeremy]

Why does it need to have a Graflok back? You don't need one to use 3.25x4.25 sheet film in holders - the plain spring-back will do fine.

Because I also have a 6x9 roll film back that I like to use for the occasional color negs and to use it I need a Graflok back.